The prior arts related to a code pattern and code patterns have been disclosed in Japan Patent Publication No. 2007-11890, U.S. Patent Publication No. US2007/026547, Taiwan Utility Model Patent Application No. 094205159, U.S. Patent Publication No. US2003/011164, and U.S. Patent Publication No. US2006/0007255.
Conventionally, when positioning marks of a code pattern are affected by the tilting or rotating of images, it often results in difficulty in identifying the positioning marks. This is when the process of image alignment is used for aligning the tilted or rotated images, which facilitates the identification of the positioning marks. However, the calculation and processing of the image alignment process is so time-consuming that it cannot be completed without the use of hardware with high computational capability.
In light of the disadvantages of prior code pattern and positioning marks, the inventor of the present invention has proposed a code pattern having a cross-shaped positioning pattern, such that five positioning marks may be readily differentiated from numerous other marks, and the cross-shaped positioning patterns of the code pattern will not become difficult to identify when images are tilted or rotated.